"use client";

/**
 * Hand-off from a homework result to the New deck flow: the content travels in
 * sessionStorage and the wizard picks it up on mount, with the options step
 * pre-filled. One-shot, like the share-target payload.
 */

export type DeckSeed = {
  text: string;
  difficulty?: "easy" | "medium" | "hard";
  count?: number;
  /** Wizard step to land on (chat's "turn into flashcards" opens options). */
  step?: 1 | 2 | 3;
};

const KEY = "freezmo.deck.seed.v1";

export function setDeckSeed(seed: DeckSeed): void {
  try {
    window.sessionStorage.setItem(KEY, JSON.stringify(seed));
  } catch {
    /* private mode */
  }
}

export function takeDeckSeed(): DeckSeed | null {
  try {
    const raw = window.sessionStorage.getItem(KEY);
    if (!raw) return null;
    window.sessionStorage.removeItem(KEY);
    const parsed = JSON.parse(raw) as DeckSeed;
    if (typeof parsed.text !== "string" || !parsed.text.trim()) return null;
    return parsed;
  } catch {
    return null;
  }
}